ST L9935 User Manual

L9935

Two-phase stepper motor driver

Features

■2 x 1.1 A full bridge outputs

■Integrated chopping current regulation

■Minimized power dissipation during flyback

■Output stages with controlled output voltage slopes to reduce electromagnetic radiation

■Short-circuit protection of all outputs

■Error-flag for over load, open load and over temperature pre alarm

■Delayed channel switch on to reduce peak currents

■Max. operating supply voltage 24 V

■Standby consumption typically 40 µA

■Serial interface (SPI)

'!0'03

PowerSO20

Description

The L9935 is a two-phase stepper motor driver circuit suited to drive bipolar stepper motors.

The device can be controlled by a serial interface (SPI). All protections required to design a well protected system (short-circuit, over temperature, cross conduction etc.) are integrated.

Table 1.	Device summary
	Order code	Package	Packing
	L9935	PowerSO20	Tube
	L9935013TR	PowerSO20	Tape and reel

April 2011

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www.st.com

Contents	L9935

Contents

1	Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		. 6
2	Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		7
3	Electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		8
	3.1	Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	8
	3.2	Thermal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	8
	3.3	Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	9
4	Application hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		11
5	Functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		12
	5.1	Basic structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	12
	5.2	Full bridge function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	13

5.2.1 No current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 5.2.2 Turning on . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 5.2.3 Chopping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 5.2.4 Reversing phase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 5.2.5 Chopper control by oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

5.3 Protection and diagnosis functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 5.4 Short from an output to the supply voltage VS . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

5.5 Diagnosis of a short to VS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

5.6 Short from an output to ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 5.7 Diagnosis of a short to ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 5.8 Shorted load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 5.9 Diagnosis of a shorted load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 5.10 Open load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

5.10.1 Over temperature pre alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

18

5.11 Application hints using a high resistive stepper motor . . . . . . . . . . . . . . . 18

5.11.1 Startup behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

5.12 Limitation of the diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 5.13 Serial data interface (SPI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

5.13.1 Startup of the serial data interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

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L9935			Contents
	5.14	Test condition for all propagation times . . . . . . . . . . . . . . . . . . . . .	. . . . . 21
	5.15	Cascading several devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . 22
	5.16	Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . 23
	5.17	Electromagnetic emission classification (EME) . . . . . . . . . . . . . . . .	. . . . 25
6	Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		. . . . 27
7	Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		. . . . 28

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List of tables	L9935

List of tables

Table 1. Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Table 2. Pin function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Table 3. Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Table 4. Thermal data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Table 5. Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Table 6. Current setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Table 7. High and low resistive motor (error bits) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Table 8. Diagnosis description - bit7 and bit6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Table 9. Test condition for all propagation times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Table 10. Full step mode control sequences and diagnosis response . . . . . . . . . . . . . . . . . . . . . . . . 23 Table 11. Half step mode control sequences and diagnosis response . . . . . . . . . . . . . . . . . . . . . . . 24 Table 12. Electromagnetic emission. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Table 13. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

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L9935	List of figures

List of figures

Figure 1. Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Figure 2. Pin connection (top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Figure 3. General application circuit proposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Figure 4. Typical average load current dependence on RSense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Figure 5. Displays a full bridge including the current sense circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Figure 6. Principal chopper control circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Figure 7. Pulse diagram to explain offset chopping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Figure 8. Normal PWM current versus short circuit current and detection of short to VS . . . . . . . . . 16 Figure 9. SPI data/clock timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Figure 10. Cascading several stepper motor drivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Figure 11. Control sequence for 3 Stepper motor drivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Figure 12. Paralleling several devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Figure 13. State diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Figure 14. EMC compatibility for L9935. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Figure 15. PowerSO20 mechanical data and package dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . 27

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Block diagram	L9935

1 Block diagram

Figure 1. Block diagram

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			32"
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			'!0'03

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L9935	Pin description

2 Pin description

Figure 2. Pin connection (top view)

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							'!0'03

	Table 2.	Pin function
	Pin No	Name			Description
	1,10,11,20	GND			Ground. (All ground pins are internally connected to the frame of the
					device).
	2	OUTA1			Output1 of full bridge 1
	3	SCK			Clock for serial interface (SPI)
	4	SDI			Serial data input
	5	SDO			Serial data output
	6	VCC			5V logic supply voltage
	7	CSN			Chip select (Low active)
	8				Enable (Low active)
			EN
	9	OUTB1			Output1of full bridge 2
	12	SRB			Current sense resistor of the chopper regulator for OUTB
	13	OUTB2			Output 2 of full bridge 2
	14	CDRV			Charge pump buffer capacitor
	15	OSC			Oscillator capacitor or external clock
	16		VS		Supply voltage
	17	NC			Not connected
	18	OUTA2			Output of full bridge 1
	19	SRA			Current sense resistor of the chopper regulator for OUTA

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Electrical specifications	L9935

3 Electrical specifications

3.1Absolute maximum ratings

	Table 3.	Absolute maximum ratings
	Symbol		Parameter	Value	Unit
	VS		DC supply voltage	-0.3 to 35	V
	VSPulsed		Pulsed supply voltage T < 400 ms	-0.3 to 40	V
	VOUT (Ai/Bi)		Output voltages	internally clamped to VS
				or GND depending on the
				current direction
	IOUT (Ai/Bi)		DC output currents	±1.2	A
			Peak output currents (T/tp ≥10)	±2.5	A
	VSRA/SRB		Sense resistor voltages	-0.3 to 6.2	V
	VCC		Logic supply voltages	-0.3 to 6.2	V
	VCDRV		Charge pump buffer voltage versus VS	-0.3 to 10	V
	VSCK, VSDI,		Logic input voltages	-2 to 8	V
	VCSN, VEN
	VOSC, VSDO		Oscillator voltage range, logic output	-0.3 to VCC+0.3	V
Note:	Note: ESD for all pins, except pins SDO, SRA and SRB, are according to MIL883C, tested at
	2kV, corresponding to a maximum energy dissipation of 0.2mJ. SDO, SRA and SRB pins
	are tested with 800V.

3.2Thermal data

Table 4.	Thermal data
Symbol		Parameter	Value	Unit
Rthj-case		Typical thermal resistance junction-to-case	5	°C/W
Rthj-amb		Typical thermal resistance junction-to-ambient (6 cm2	35	°C/W
		ground plane 35 µm thickness)
		Typical thermal resistance junction to ambient (soldered on a
Rthj-amb, FR4		FR 4 board with through holes for heat transfer and external	8	°C/W
		heat sink applied)
TS		Storage temperature	-40 to 150	°C
TSD		Typical thermal shut-down temperature	180	°C

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L9935	Electrical specifications

3.3Electrical characteristics

8 V ≤ VS ≤ 24 V; -40 °C ≤ Tj ≤ 150 °C; 4.5 V ≤ VCC ≤ 5.5 V, unless otherwise specified.

Parameters are tested at 125 °C. Values at 140 °C are guaranteed by design and correlation.

Table 5.

Electrical characteristics

Symbol

Parameter

Test condition

Min.

Typ.

Max.

Unit

Supply

Total supply current I

S

+ I

VS = 14 V;

EN

= HIGH;

IS85

(both bridges Off)

VCC

TJ ≤ 85 °C

-

40

100

μA

ISOP

Operating supply current

IOUT Ai/Bi = 0; fOSC = 30 kHz

-

4.5

-

mA

VS = 14 V

ICC

5 V supply current

= LOW

-

1.4

10

mA

EN

Full bridges

ROUT, Sink

RDSON of sink transistors

Current bit

-

0.4

0.7

Ω

ROUT, Source

RDSON of source transistors

combinations LL, LH, VS ≥12 V

-

0.4

0.7

Ω

ROUT8, Sink

RDSON of sink transistors +

Current bit combinations LL,

-

1.6

3

Ω

RDSON of source transistors

LH, VS = 8V

= HIGH; IFWD = 1 A;

VFWD

Forward voltage of the DMOS

EN

-

1

1.4

V

body diodes

VS ≥12 V

VREV

Reverse DMOS voltage

EN = LOW IREV = 1 A

-

0.5

0.9

V

tr, tf

Rise and fall time of outputs

0.1...0.9 VOUTVS= 14 V

0.3

0.6

1.5

μs

OUTAi/Bi

Chopping 550 mA

Switch Off threshold of the chopper (R1 R2 = 0.33 Ω)

VSRHL

Voltage drops across R

R (1)

Bit 5, 2 = H; Bit 4, 1 = L

12

20

35

mV

1

2

VSRLH

(Voltage at Pin SRA or SRB vs.

Bit 5, 2 = L; Bit 4, 1 = H

160

180

210

mV

GND)

VSRLL

Bit 5, 4, 2, 1 = L

270

300

340

mV

Enable input

EN

VEN High

High input voltage

-

VCC -

-

-

V

1.2V

VENlow

Low input voltage

-

-

-

1.2

V

VEN Hyst

Enable hysteresis

-

0.1

-

-

V

IEN High

High input current

VHigh = VCC

-10

0

10

μA

IEN Low

Low input current

VLOW = 0V

-3

-10

-30

μA

Logic inputs SDI. SCK, CSN

VHIGH

High input voltage

2.6

8

V

VLOW

Low input voltage

= LOW

-0.3

1

V

EN

VHyst

Hysteresis

0.8

1.2

1.6

V

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